/**
* Takes the input list of words and processes it, returning a list of {@link Frequency}s.
*
* <p>This method expects a list of lowercase alphanumeric strings. If the input list is null, an
* empty list is returned.
*
* @param words A list of words.
* @return A list of word frequencies, ordered by decreasing frequency.
*/
public static List<Frequency> computeWordFrequencies(String text, boolean useStopWords) {
List<String> words = Modified_Utilities.tokenizeFile(text, useStopWords);
for (String st : words) // for every word in words:
{
// check if the word is in the lstStr(if has appeared once)
// if not, add it to lst and lstStr
if (findIndex(st) == -1) {
lst.add(new Frequency(st, 1));
}
// if yes,increment the frequency of that word
else {
// use lstStr to get the index of the Frequency of that word in the lst
int index = findIndex(st);
Frequency temp = lst.get(index);
temp.incrementFrequency();
lst.set(index, temp);
}
}
Collections.sort(lst, new FrequencyComparator()); // sort the list using a custom Comparator
return lst;
}
public int compare(Frequency a, Frequency b) {
int freComparison = b.getFrequency() - a.getFrequency();
// Firstly, sort the Frequency objects according to their frequency,
// if they have the same frequency, sort them by their text
return freComparison == 0 ? a.getText().compareTo(b.getText()) : freComparison;
}